Efficient and secure conference-key distribution

Carlo Blundo, Antonella Cresti

Shahrokh Saeednia, Reihaneh Safavi–Naini

Wen-Guey Tzeng, Zhi-Jia Tzeng

Xing Qin

We focus on unconditionally secure conference key distribution. Many onetime keys shared by users are needed for perfect secure communication. Our approach is to use a twoparty key agreement system as an underlying cryptographic primitive and extend it to a conference system which is as secure as the twopart system. With the spanning tree in this paper, the conference key distribution system can be executed in parallel to the largest extent and it is efficient for dynmaic changing group.

Shahrokh Saeednia, Reihaneh Safavi–Naini, Willy Susilo

Yuanbo Guo, Jianfeng Ma

A computationally secure and robust conference key distribution scheme is presented, which requires only the authenticated and encrypted point-to-point channels between each server and each user. By using it, every honest user of a conference can get a common key after running of the protocol, even if some minority of the servers malfunction or misbehave. Analysis shows that a passive adversary gets zero knowledge about the conference key, and the active adversary cannot impersonate successfully. Because this scheme is noninteractive, both operation and communication overhead are reduced, this make it very efficient.